The 26-year-old Hurd was arrested after allegedly accepting a kilo of cocaine from an undercover federal agent, according to a criminal complaint that says the player was first identified as a potential drug dealer over the summer as the NFL lockout was coming to an end.

Teammates said they were stunned by the allegations, and Angelo said he was, too.

"There were no facts, there were no flags, that anybody could present tangibly to say we should have known otherwise, and I want to make that perfectly clear to the public, to our fans," Angelo said Friday. "We do our homework. We do our due diligence. We did everything you could possibly do given the information that we can allocate."

Hurd was in his first year with the Bears and sixth year overall in the NFL after five seasons with the Cowboys. Angelo said the Bears performed an extensive background check on Hurd, a San Antonio native who played at Northern Illinois, before signing him in July to a three-year deal reportedly worth up to $5.15 million, including a $1.35 million signing bonus and base pay this season of $685,000.

Asked to respond to rumors that Hurd was dealing to other players on the Bears or around the league, Angelo said, "I can't talk about that."

"I'm certainly not going on any witch hunts about players," he added. "The one thing that we've done when there's been a wrong, we've acted. We don't justify wrongs. We've acted. We have a track record of doing that. Unfortunately, a situation arose that caught us off guard, but not to the point where we aren't going to do the right thing."

Hurd's defense attorney, David Kenner, disputed a report that authorities have a list of NFL players with a connection to Hurd.

Receiver Earl Bennett described Hurd as a "guy with high character who just loves to play the game of football, loves to have fun." Bennett also said he doesn't think other players are involved.

"I wouldn't think so," he said. "A lot of guys in this locker room are very high-character guys."

Coach Lovie Smith echoed that sentiment.

"We have a great group of guys," he said. "But sometimes when you're dealing with this many, it's hard to have all the players be a certain way. But you can't let that scar what else we're getting done here. It's always about the team. Every once in a while a guy will go outside what's best for the football team and there are consequences that you deal with. That's how life goes. There are life lessons that are being learned here by our football team."

Former NFL receiver Terrell Owens played three seasons (2006-08) with Hurd in Dallas.

"Like everyone else, I was shocked and extremely saddened with the news of his arrest," Owens said in a statement. "I have not been able to reach him but hope to speak to him soon. I have spent much time with him and know his family. It would never cross my mind that Sam would ever be dealing or using drugs.This is completely out of character for him."

The Drug Enforcement Administration on Friday said it is joining the investigation of Hurd.

In a statement released Friday, the special agent in charge of the DEA's Chicago office said the DEA will assist the U.S. Department of Homeland Security. Special Agent Jack Riley promised that the investigation would be treated like any other drug-trafficking case and that anybody who breaks the law will go to jail -- whether they're a professional athlete or not.

Hurd told the agent that he was interested in buying five to 10 kilograms of cocaine and 1,000 pounds of marijuana per week to distribute in the Chicago area, the complaint said. He allegedly said he and a co-conspirator already distribute about four kilos of cocaine every week, but their supplier couldn't keep up with his demands. A kilogram is about 2.2 pounds.

Kenner said Hurd intends to fight the charges. He is expected to be tried in Texas, where the criminal complaint was filed this week by the U.S. attorney.